Take a look at the citified parts of Farm-to-Market Roads 2252 or 1093, and you'll see plenty in the way of markets and not much in the way of farms.

The busy routes, known respectively as Perrin Beitel Road/Nacogdoches Road in San Antonio and Westheimer Road in Houston, were built as part of a nearly 41,000-mile system that began 71 years ago to do just what the name implies — connect rural and urban areas.

While not quite unique — Missouri and Iowa have variations on the theme — farm-to-market roads (and their Western cousins, ranch-to-market roads) are Texas originals, dating back to a 5.8-mile stretch of Rusk County timber highway completed in 1937.

Most states have four basic highway types: interstate, U.S., state and county roads. In addition to standard state highways, Texas "has a ton of different road classifications," said Gene Hawkins, a research engineer at the Texas Transportation Institute.

"We have farm roads, which can also be ranch roads. We have spurs. We have loops," he said, not to mention business routes, park roads, recreational roads and one-of-a-kinds such as NASA Road 1.

The farm-to-market system came into being in 1945 and was expanded with the Colson-Briscoe Act in 1949, which set aside $15 million per year for construction (think $173 million in today's dollars).

Another category is "urban roads," which includes about 1,600 miles of developed FMs such as 2252 and 1093. In 1995, the Texas Department of Transportation proposed renaming those routes with the new classification and removing the familiar FM road signs with the state outline.

The reaction was overwhelmingly negative, particularly in the Houston area, where suburban routes such as FM 1960 had become ingrained. Residents didn't like the sound of "UR 1960" and wanted to keep the signs.

"After the public made us better aware of the importance of the name, we simply took care of the issue internally so we can keep track of roads," department spokesman Randall Dillard said, noting that urban FMs are eligible for state maintenance but not for state expansion money.

The vast network of FM and RM roads poses a challenge. They make up more than half the road mileage under state maintenance, but Dillard said they carry less than 15 percent of the traffic, forcing the state to make difficult maintenance decisions.

Still, they allow for a little bragging.

"Our farm-to-market system is bigger than a lot of total highway systems in other states," Dillard said.